Incinerators

By Maddie L, Ian, Sam F, Alex F



Incinerators are used all over the world to burn trash and other waste. Some Incinerators generate energy from the burning of waste, these plants are called waste-to-energy plants. Incinerators reduces the volume of waste by about 90 percent and weight by 75 percent. There are eight types of incinerators, fixed-hearth incinerators, rotary kiln, plasma arc, liquid injection, fluidized bed, multiple hearth, catalytic combustors, and static heart incinerator. In 1885 the U.S. Army created the first garbage incinerator in New York Harbour.
Incineration is one of the most common ways of the disposal of trash. The state of Massachusetts generates on average 8 million tons of waste and two thirds of that is burned in incinerators. Currently in Massachusetts, there are seven facilities with a municipal waste combustor. Incinerators can have a harmful effect on the envirment. Incinerators can release up to 190 differnt chemicals into the sky such as lead, mercury, and arsenic. Incinerators liquify materials which may end up in watersheds causing water pollution. Incineration can leave behind dangerous materials that need to be put into special landfills.


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This video shows the effect of a garbage incinerator in Tulsa. This picture is of the incineration process.


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The image above is a diagram of how many waste management projects were funded during 2000-2006



Plasma Arc Incineration:

Plasma arc incinerators ionize inert gases via an electric arc between two electrodes. This plasma creates an extraordinary amount of heat, ranging from 3000-7000˚ Celsius. The extreme heat can easily break down organic compounds into their basic atoms, which later recombine to form gases such as CO2. Inorganic material is left as a stable, leach-resistant slag. Concerns surrounding plasma arc incineration include ensuring that gas emissions are minimal and cleaned before being released to the atmosphere.
http://www.cpeo.org/techtree/ttdescript/plarctech.htm

Here is a diagram of a Plasma Arc Incinerator:Plasma_Arc_Incinerator_Diagram.jpg
Waste is fed into the pregasifier, which processes 80% of organic material into syngas, later used for burning or other purposes. After the pregasifier, waste enters the main plasma arcing section where waste is broken down by high temperature arcs of electricity between two carbon electrodes. The byproducts, glass and metal, are gathered and disposed of, since they are primariy used for shielding inorganic materials. The thermal residence chamber is where the syngas is filtered before it gets cleaned and applied to liquid fuel production, converted to hydrogen, or electric generation. (PEM merely stands for Plasma Enhanced Melter). This design is simply one example of plasma arc incinerators, and more broadly, incinerators in general.
http://www.inentec.com/pemtm-technology/process-details.html
Cons of Plasma Arc Incineration:
Plasma arc incineration produces a synthetic gas, or syngas, which contains toxins.
http://greenaction.org/incinerators/documents/GreenactionGAIAExposeOfFloridaPlasmaArcIncineratorInDisguiseProposals030908.pdf


What are other uses for incinerators?
Along with burning trash, Incinerators can also be used to burn medical equiptment, non-hazardous waste, warm buildings and even dispose of drugs.

Incinerators also produce jobs for people in the US. More info can be found at -->
http://www.census.gov/econ/industry/ec07/a562213.htm


Pros and Cons of Incinerators: (taken from website below cons)

Pros:

Energy Conversion

  • Incinerators can turn garbage into electricity through the incineration process, thereby taking a useless item (trash) and turning it into electricity, a highly used and valuable resource. Incinerators burn garbage 24/7 and therefore produce a constant stream of electricity. A 250-ton per day incinerator can produce almost 6.5 megawatts of electricity daily and save about $3 million to $5 million in fuel annually, according to Terry Ally.

Waste Reduction

  • A main argument for the use of incinerators is that they can greatly reduce the volume of waste in solid form by converting it to a gas form. Incinerators take the waste that would be occupying landfills and puts it into the incinerator, where the emissions are controlled and limited in the amount that makes it into the atmosphere. Landfills are eyesores, have horrible smells, and much of the material takes hundreds, if not thousands of years to decompose.
Cons:

Community Impact

  • Incinerators are massive buildings that can create a negative and unwanted impact on surrounding residential areas. Incinerators have been known to create falling ash in the area from leaked emissions. In addition, their presence is a major deterrent to attracting residents to the area, as they are inundated with the constant flow of large trucks as well as the unpleasant sight of industrial machinery. Also, workers at incineration plants report getting sick from the fumes.

Air Pollution

  • All types of incinerators cause some type of air pollution, and can put up to 190 different types of chemicals into the air at one time, according to Groundwork, an environmental group. Of particular concern is the highly toxic fly ash. This ash must be safely disposed of, which usually requires the need for specialist toxic waste landfill elsewhere. Incinerators also emit varying levels of heavy metals into the atmosphere, such as vanadium, manganese, chromium, nickel, arsenic, mercury, lead and cadmium. All of these metals can be toxic at varying levels.
  • The proposed Fibrominn Project is estimated to release 388,000 lbs. of sulfuric acid, 236,000 lbs. of hydrochloric acid, and 4,600 pounds of hydrofluoric acid per year,amongst other contaminants

Read more: Pros & Cons of Incinerators | eHow.com http://www.ehow.com/list_6811674_pros-cons-incinerators.html#ixzz1uNtYk5oC ,
http://www.energyjustice.net/fibrowatch/toxics.html

Environmental, Human, and Financial Impact of Incinerators:

Bottom ash that is created, is around 10% in volume and 20-35% in weight when compared to the original material fed into the incinerator. Resulting pollutants from the burning process are created at various stages of the incineration process, and require specialized landfills for disposal. Such incinerators release the pollutants into the environment, which can contaminate many different food and water sources for humans and animals, and are ultimately consumed by such creatures. Dioxins are of particular concern, since they are a most lethal Persistant Organic Pollutant, and can be exposed to people through ingestion of contaminated food or water, consuming fish or wildlife contaminated by air emissions, or directly breathing in the contaminated air. Dioxins can also travel vast distances across oceans and land through water and air currents, making them global contaminants. Up to $500,000,000 could be used on an incinerator, where half of that money is spent solely on the control of various heavy metals such as lead, mercury, and cadmium, and other toxins including furans, volatile organic compounds, and dioxins in waste emissions. Ashes left over from the incineration process is buried at landfills, while effluents are treated before being discharged into lakes or river.
Waste-to-energy power plants use water as a coolant and in boilers, when this water is discharged from the facility the water temperature is at higher temperatures than average. The water may also be carrying polutents. This water discharge can harm aquatic life and can reduce water quality.
http://window.state.tx.us/specialrpt/energy/renewable/municipal.php
http://www.alternative-energy-news.info/negative-impacts-waste-to-energy/
http://www.greenpeace.org/international/en/campaigns/toxics/incineration/the-problem/

Types of Incinerators
  • Fixed-Hearth Incinerators
Most usuallly used in the city, more specifically hospitals, and other large untilities. Tempatures can climb up to a height of 2,000 degrees F. The heat is generated by burners usally running on natrual gas.
  • Rotary Kiln
Also are used to immediatly decompose solids and liquids, but unlike a fixed-hearth incinorator, the rotary kiln incinorator is a long cylinder layed on its side which uses rotation as its method to break down tough substances. Tempatures within this incinerator vary from 1,300 to 2,400 degrees F. It is also the most commonly used incinerator.
  • Plasma Arc
These incinerators involve an electric arc between two electrodes which ionizes an inert gas, creating temperatures between 5432 degrees F to 12632 degrees F, at which point, molecular bonds between atoms are broken, and organic materials become seperated from inorganic materials.
  • Liquid injection
Can Decompose most solids by turing these substances into small particles and mixing it with chemicles. Temperatures can be anywhere from 1,200 to 3,000 degrees F.
  • Fluidized Bed
Can Dispose of liquids, Solids, Gases, and Sludge. Substances that melt cannot be gotten rid of using this method of incieration because of its interference with the process. Tempature ranges from 1,400 to 1,800 degress F.
  • Multiple Hearth
The substance is dumbted into the hole in the top of the incinerator and it channels enough heat to burn the substance. It is the most fuel-efficient way of disposing of solids, liquids, gases, sludges and tars. It operates in 1,400 to 1,800 degrees F.
  • Catalytic Combustors
It can eliminate more then half of the air pollution in the surrounding area, however it can only work to its greatest extent if turned up to 1,000 degrees F.
  • Static heart incinerator
Can dispose of liquids and gas. It is a well liked incinerator for its lack of ash producing system. Its tempature remains between 1,100-1,200 degrees C.

*an older method of incineration was the fixed-grate incinerator. It is a smaller incinerator found in city apartments or small complexes. Although many of these incinerators have been replaced due to newer models.

Are Incinerators harmful?


According to the HPA's (Health Protection Agency) study in 2009 on air pollution, Incinerators aren't a significant threat to public health. The article goes on to say:
**INCINERATORS that are well run and regulated do not pose a significant threat to public health, according to air pollution experts.**

On the contrary, incinerators do come with several problems as Kim Leslie of eHow explains:

Loss of Resources

    • In some cases, recyclables are removed before incineration of waste. By incinerating things that could have been reused, resources are lost.

Air Pollution

    • Incinerators release dioxins/furans, sulfur dioxide, hydrochloride, cadmium, lead, mercury, nitrogen oxide, particulate matter and carbon oxide into theair,contributing to global climate change.
    • Picture from POLLUTION ISSUES

Toxic Materialsincinerators.jpg

    • Incineration can't make waste disappear. There is always ash left and metals. This waste is considered hazardous by the Environmental Protection Agency. This waste is stored sometimes in special landfills and sometimes in special buildings.

Water Pollution

    • Incineration also liquefies some materials that can end up in watersheds as the waste water can't be processed by sewage treatment plants effectively.

Job Loss

    • Incineration removes products from recycling streams and can potentially reduce the number of jobs in an area.
Read more:Problems With the Incineration of Waste | eHow.com http://www.ehow.com/facts_5118657_problems-incineration-waste.html#ixzz1uTHuBz3

Potential stakeholders in Incinerator Technology Include:

  • County/Distric Councils
  • The Health Protection Agency
  • The Environment Protectoin Agency
  • The Energy Companies

History

  • In 1885, the U.S army created the the first garbage incinerator was built on Govorners Island, New York harbour. By the 1930's there were roughly 700 incinerators nation wide. This number decreased to about 265 by 1996 due to air quality problems and limitations of technology. During the 1970's with the energy prices increasing, waste combustion grew in popularity as a way to create cheaper energy. In 1975, the first privetly built waste-energy plant opened in Masschussets. During the 1980's funds became available to support the creation of waste-to-energy plants, these funds help create more plants. Howevor, by 1986 the funds were discontiuned this signuled that fewer and fewer waste-to-energy plants would be created.

Accidents

  • In 1995, a 90 ton-per-day incinerator exploded, this accident cost one man his life and two others were severly injurned. The accident took place during a repair of the furnace ash chute damper. Water was injected to remove blockage and the water reacted with aluminum ash, which formed hydrogen. The hydrogen caused the explosion.The probable cause for this accident was either human error or deficiency in procedures.
  • Later, in 2011, a waste incinerator in Rotherham exploded, injuring a 42 year old man and a 50 year old man. The 42 year old man died at the hospital after being airlifted, and the 50 year old man sustained serious injuries from the blast.
http://www.bbc.co.uk/news/uk-england-south-yorkshire-121643